NOTE: If you are installing this guard on the currently installed pan, skip ahead to step 3.
Begin by making sure your new skid guard is free from contaminants. Prep and remove all paint from the areas to be welded.
Clean up your welds, scuff pan and guard. PAINT! It's not necessary but keep in mind that your pan and the guard are mild steel and will rust if not coated.
Jack up your car and place jack stands and block up your wheels if you are not going up on all 4. Be sure to give yourself as much room as you can under your car it will make your life easier. Next drain your oil and if your drain plug looks anything like this, get a new one. They are cheap it's worth it.
Pull off your flywheel dust cover to gain access to all of your oil pan mounting bolts.
Remove all oil pan mounting hardware. Use a flat head screw driver or scraper to remove the oil pan from the block. Running a razor blade around the perimeter of the pan may aid in this process.
If you are using a new pan you can apply sealant directly. If you are using your old pan your will need to clean off any old sealant and use black RTV silicone or equivalent to reseal the pan. Re-torque all pan bolts to 15ft/lb using an alternating pattern.
There is no step 7 your done :-P. Get your car back on the ground safely, put oil in it and hit the track.